Technical difference between mobile to mobile and mobile to PSTN/Fixed line call?

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Below is the description of the call set-up procedure for a call from a PSTN subscriber to a mobile subscriber.

1. The PSTN subscriber keys in the MS’s telephone number (MSISDN). The MSISDN is analyzed in the PSTN, which identifies that this is a call to a mobile network subscriber. A connection is established to the MS’s home GMSC.Now the call has entered the dialled party’s network
2. The GMSC analyzes the MSISDN and queries the HLR for information about how to route the call to the serving MSC/VLR.
3. The HLR translates MSISDN into IMSI, and determines which MSC/VLR is currently serving the MS. The HLR also checks if the service, “Call forwarding to C–number” is activated, if so, the call is rerouted by the GMSC to that number.
4. The HLR requests an MSRN from the serving MSC/VLR.
5. The MSC/VLR returns an MSRN via HLR to the GMSC.
6. The GMSC analyses the MSRN and routes the call to the MSC/VLR.
7. The MSC/VLR knows which LA the MS is located in. A paging message is sent to the corresponding BSC.
8. The BSC’s distribute the paging message to the BTS in the desired LA.
9. When the MS detects the paging message, it sends a request on RACH for a SDCCH.
10. The BSC provides a SDCCH, using AGCH.
11. SDCCH is used for the call set-up procedures.
12. The MSC/VLR instructs the BSC to allocate a TCH.The BTS and MS are told to tune to the TCH. The mobile phone rings. If the subscriber answers, the connection is established.

For more details on MS-PSTN call or PSTN-MS or MS-MS call refer attached document......

So many thanks for the detailed answer. So I guess it's mostly like mobile to mobile call, except in the terminating side it's a telephone. Thank you for the file on call flow. I will download after gathering enough points.